Application:Pure juice fermentation, such as white wine fermentation, red wine secondary fermentation,preventing back-flush into the fermentation chamber during ambient temperature changes in the room.This style airlock is typically used on fermenters up to 20 Gallon. Usage: Fill water into the exhaust valve, insert to the cover of the brew barrel or rubber plug on the top of the fermentation container, cover with the lid. Function:Isolate the air from the wine/beer, discharge CO2, prevent flies flying into the wine/beer Usage: 1.After sterilized adding water to the exhaust valve . 2.After both sides of the exhaust valve's water in the parallel state, gently insert the brewing bucket lid. 3.When wine was ferment generated bubbles, through the exhaust valve discharged to buckets outside , 4.All the fermentation process is in normal temperature, automatic fermentation , exhaust, without manual control. 5.Can be used for home-brewed beer, wine, cider and other uses. colour:White + red Material:plastic size:Length: 17cm Lower mouth diameter: 10mm Package Contents: 4 x S-Shape Air Lock with snap-on caps Note: Please use boiled water to boil and disinfect the Air Lock before you using it. And clean it with water after using. Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.